The field of the invention is that of turbine engines, and more particularly that of turbine engine blades made of composite material, and the present invention relates more particularly to metal structural reinforcement for the leading edge of a turbine engine blade.
It should be recalled that the leading edge corresponds to the front portion of an aerodynamic profile that faces the air stream and that splits the air flow into a pressure side air flow and a suction air flow. In contrast, the trailing edge corresponds to the rear portion of an aerodynamic profile where the pressure side and suction side flows rejoin.
Turbine engine blades, and in particular fan blades, are subjected to high levels of stress, in particular of mechanical stress. Thus, it is known to fit fan blades made of composite material with metal structural reinforcement extending over the full height of the aerodynamic profile and fitting closely to the shape of the leading edge, as mentioned in application FR 2 732 406 in the name of the Applicant. Such metal structural reinforcement serves to protect the set of composite blades in the event of a foreign body impacting against the fan, such as for example a bird, hail, or indeed stones. In particular, the metal structural reinforcement protects the leading edge of a blade made of composite material so as to avoid any risk of delamination, of fiber breakage, or indeed of damage resulting from loss of cohesion between fibers and a matrix.
In conventional manner; the metal structural reinforcement is a metal part made of titanium constituted by two stamped metal sheets of TA6V type alloy that are welded together at high temperature so as to form a single block of material. Unfortunately, such a part is heavy, but nevertheless it can happen that it is still not strong enough, particularly with increasing size of resin transfer molded (RTM) blades, in particular for turbine engines of very large dimensions, or when the length and the width of the blade increase substantially. Furthermore, it then presents material density that is unvarying, which is not well adapted to the shape of a leading edge, which shape varies along its height.